/**
 * Logback: the reliable, generic, fast and flexible logging framework.
 * Copyright (C) 1999-2013, QOS.ch. All rights reserved.
 *
 * This program and the accompanying materials are dual-licensed under
 * either the terms of the Eclipse Public License v1.0 as published by
 * the Eclipse Foundation
 *
 *   or (per the licensee's choosing)
 *
 * under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation.
 */
package ch.qos.logback.core.encoder;

import java.io.IOException;
import java.io.OutputStream;

import ch.qos.logback.core.spi.ContextAware;
import ch.qos.logback.core.spi.LifeCycle;

/**
 * Encoders are responsible for transform an incoming event into a byte array
 *
 * @author Ceki G&uuml;lc&uuml;
 * @author Joen Huxhorn
 * @author Maarten Bosteels
 *
 * @param <E>
 *          event type
 * @since 0.9.19
 */
public interface Encoder<E> extends ContextAware, LifeCycle {

  /**
   * Get header bytes. This method is typically called upon opening of
   * an output stream.
   *
   * @return header bytes. Null values are allowed.
   */
  byte[] headerBytes();

  /**
   * Encode an event as bytes.
   *
   * @param event the log event
   */
  byte[] encode(E event);

  /**
   * Get footer bytes. This method is typically called prior to the closing
   * of the stream where events are written.
   *
   * @return footer bytes. Null values are allowed.
   */
  byte[] footerBytes();
}
